A PROJECT REPORT ONDesign of mechanical components of Steering controlled headlights

FROM 1ST JAN 2014 TO 31ST MAY 2014ATY.M.C.A. University of Science & TechnologyFaridabad (121006)IN THE PARTIAL FULLFILLMENT OF THE AWARD FOR THE DEGREE OF

BECHOLAR IN TECHNOLOGYIN DEPARTMENT OF MECHANICAL ENGINEERINGUNDER THE GUIDENCE OF Dr. KRISHAN VERMASUBMITTED BYJITENDER MALIK (M-402-2K10)KANIKA BOORIA (M-406-2K10)KULDEEP YADAV (M-409-2K10)KUNDAN KUMAR (M-410-2K10)MANSI SINGH (M-418-2K10)MEGHNA MALLA (M-421-2K10)

ABSTRACTThe topic of this project is steering controlled (or directional) headlights, that are usually a separate set ofheadlights fitted to roadvehicles beside the usual low beam/high beam headlights and their feature is that they turn with the steering, so that the driver of the vehicle can see the bend, what he is actually turning into.These type of headlights appeared on production cars in the 1920s and are still around nowadays, but not very popular, although they make nighttime driving safer. The most famous car which featured these lights was the Citroen DS(1955-1975), introduced on the 1968 Paris Motor Show. The headlights can be connected to the steering linkage by means of rods orcables, operated hydraulically by the power steering or nowadays electronically adjusted, even controlled by satellite navigation system. Our project is to make new and modern Directional Headlights in efficient manner by increasing the light angle. Directional headlights are those headlights that provide improved lighting especially for cornering. There are automobiles that have their headlights directly connected to the steering mechanism so that its lights will follow the movement of the front wheels.Our project comprises Cam and Follower mechanism, Gear mechanism and spring mechanism. Cam and Follower mechanism is used to turn the head lights to right or left direction, Gear mechanism is used to transmit motion and to reduce the no of rotations from steering rod to cam shaft. Spring mechanism is used to bring back the follower and head light bracket to its initial position.According to our project, when the steering steers to the right, the light bracket at right alone steers to right using cam & follower mechanism and reduction gears & vice versa. At the same time the left bracket remains stand still due to the dwell period of the cam. During the return stroke of cam, the spring mechanism is used to bring the bracket and follower to its initial position. The reduction gears are used to turn the brackets to the required angle respective to the steering rotation.Our project will be useful for vehicles, which are been used in hill areas The 1968 Citroen DSfeaturing directional- headlightsINTRODUCTIONThe present invention relates to headlights of an automobile, more particularly to a direction turning device for headlights of an automobile which enables to turn direction synchronously with the rotation of the steering and hence increasing the safety for driving at night or in the darkness.In the known technology of the prior art, a headlight of an automobile has a fixed line of emission which is aligned with the front direction of the automobile. Although the effects of "high beam" or "low beam" can be achieved by adjusting the angle of elevation of the headlight, the direction of emission is not adjustable as to the left or right. When the road curves or turns, the corner on time when the car turns, thereby creating a dead angle of illumination and such lack of visibility poses danger in driving at night or in darkness.Therefore, it is highly desirable to invent a device to solve this problem and such device is of high utility.An object of the present invention is to provide a direction turning device for a headlight of an automobile which renders to emission direction of a headlight of an automobile in synchronization with steering and thus increases the illuminated area upon changes of direction of the automobile when the automobile makes turns.In ancient Directional headlights, when the steering steers to right or left direction, then both the right and left headlights will steer to the perspective directions. It results in altering the optical axis of the head light to the vehicle speed and the front road-shape.But according to our project, when the steering steers to right then the right side of the headlight bracket steers to right side and the left side headlight bracket remains stationery by cam mechanism and it is similar for the other side also. Because of this, the optical axis of the headlight is widened and it is useful for the drivers for safety ride.

LITERATURE REVIEWThe present invention relates to a vehicle front lamp light distribution control system and more particularly to a vehicle front lamp light distribution control system capable of raising visibility at the time of cornering by controlling light distribution means of the front lamp.According to- Japanese Patent Publication No. H5-23216, Japanese Patent Application Laid-Open No. H8-183385, Japanese Patent Application Laid-Open No. H11-78675, and Japanese Patent Application Laid-Open No. H8-192674 A vehicle head lamp including a fog lamp is provided with a movable reflector and by turning the movable reflector in the steering direction by an amount corresponding to a steering angle of the steering wheel, the light distribution pattern of the front lamp is changed in the direction of vehicle's turn so as to raise visibility at the time of cornering.However, according to the aforementioned earlier art, the light distribution pattern of the front lamp is changed in the steering direction of the steering wheel by an amount corresponding to the steering angle when the vehicle turns on an intersection or the like, cornering destination cannot be beamed brightly enough before operating the steering wheel. Therefore, an art capable of beaming the cornering destination prior to operation of the steering wheel has been demanded.Czech Tatra and 1920s Cadillacs were early implementer of such a technique, producing in the 1930s a vehicle with a central directional headlamp. The American 1948 Tucker Sedan was likewise equipped with a third central headlamp connected mechanically to the steering system. The 1967 French Citron DS and 1970 Citron SM were equipped with an elaborate dynamic headlamp positioning system that adjusted the headlamps' horizontal and vertical positioning in response to inputs from the vehicle's steering and suspension systems, though US regulations required this system to be deleted from those models when sold in the USA.

HISTORY OF DEVELOPMETAlthough the concept of headlights that follow the movements of the steering is still considered nowadays as being innovative, itis not new. Thefirst vehicles fittedwith such systems appeared in the 1920s. Pioneers and milestones in the automotive history featuring directional headlights were the 1928 Willys - Knight 70ATouring, the 1930s Czech Tatra and the American 1948 Trucker Sedan. These cars were equipped with athird central headlight mechanically connected tothe steering system. The most famous car featuring directional headlights, was theCitroen DS (1955-1975), introduced on the 1968 Paris Motor Show. This car had both headlights not only swiveling with the steering, but they were self leveling as well, responding to inputs from the suspension. While it was apurely mechanical system operated by cables, the 1970Citroen SM used asealed hydraulic system with a glycerin based fluid. On present day motorcars two types of directional headlight system are inuse:1. A fixed light that only turnson and off based on steering and vehicle speed.2. The light is motorized by the use of small electricmotors and physically swivels according to the movement ofthe steering wheel and vehicle speed.This modern technology first appeared in 2003 onthe Porsche Cayenne (fixed) and the Mercedes E-class (motorized). Soon other manufacturers followed them such asthe BMW with theadaptive headlights and cornering lights and nowadays most of themain brands use such systems on their vehicles like Acura, Audi, BMW, Cadillac, Ford, Infiniti,Jaguar, Land Rover, Lexus, Mercedes-Benz, Opel, Porsche, Saab, Volkswagen, Volvo and Mazda. Audi is experimenting with asystem which uses satellite navigation adjust the headlights according to the road layout ahead thevehicle

CONSTRUCTIONThe main components used in this project are:1. Spur Gears:Spur gears are the simplest, and probably most common, type of gear. Their general form is a cylinder or disk. The teeth project radically outward, and with these "straight-cut gears", the leading edges of the teeth are aligned parallel to the axis of rotation. These gears can only mesh correctly if they are fitted to parallel axis.

2 Sprockets:A sprocket is a profiled wheel with metal teeth that meshes with a chain, track or other perforated or indented material. Sprockets are used to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc.

3 Cam & follower:Cams are basically shaped surfaces that are typically not round follower(possibly a small wheel) is displaced as it moves over the surface.

4 Steering system:The most conventional steering arrangement is to turn the front wheels using a handle operated steering wheel which is positioned in front of the driver, via the steering column, which may contain universal joints to allow it to deviate somewhat from a straight line.Other arrangements are sometimes found on different types of vehicles. For example, a tiller or rear wheel steering.Tracked vehicles such as tanks usually employ differential steering that is, the tracks are made to move at different speeds or even in opposite directions to bring about a change of course.

5 Light brackets: Headlamps must be kept in proper alignment (or "aim"). Regulations for aim vary from country to country and from beam specification to beam specification. This gives all vehicles roughly equal seeing distance and all drivers roughly equal glare.

6 Frames:Framing, in construction known as light frame construction, is a building technique based around structural members, usually called studs, which provide a stable frame to which interior and exterior wall coverings are attached, and covered by a roof comprising horizontal joists and sloping rafters or manufactured roof trusses covered by various sheathing materials. Light frame material dimensions range from 38 mm by 89 mm (1.5 by 3.5 inches i.e. a two-by-four) to 5 cm by 30 cm (two-by- twelve inches) at the cross-section, and lengths ranging from 2.5 m (8 feet) for walls to 7 m (20 feet) or more for joists and rafters.

7 Chain drive:Commonly, mechanical energy from a motor or other source applied to a sprocket wheel is conveyed by means of an endless chain to another sprocket wheel for driving a mechanism. Examples of such an arrangement are found in bicycles, motorcycles, and conveyor belts.The chain in this application is so designed that each consecutive link fits over a sprocket, the distance between links being called the pitch. The relative speed of the wheels varies according to their relative circumferences and, thus, the number of sprockets on each.

WORKING PRINCIPLE:Our project is to the turn the right light bracket to the right, when the vehicle turns to right leaving the left bracket to remain in standstill position, and vice versa.When the steering steers to the right, a sprocket attached to the steering rod rotates which in turn connected to the other sprocket through a chain. The sizes of the sprockets were designed in such a way that, if the smaller sprocket rotates four full complete rotations the larger sprocket will rotate once. Also the small gear, which is attached to the same shaft as of the larger sprocket, also rotates along with the sprocket. A larger gear of the former is chosen, which is twice its diameter, is meshed to transmit the motion. After this, the rotation of cam is achieved by fixing the cam in the same shaft of the larger gear. The spherical edged follower is attached to the cam is used to convert the rotary motion of cam into reciprocating motion. So the right light bracket moves according to the movement of the follower. At the same time, the cam at the other end remains in the dwell period, which results in the stand still position of the light brackets.The light bracket will returns back to its original position, using the spring mechanism attached to it.When the vehicle turns to left, the left bracket alone turns to the left leaving the right light bracket in standstill position.

INITIAL HEADLIGHT POSITIONFINAL HEADLIGHT POSITION

DESIGN CALCULATIONS1. Design calculation for chain driveSpeed of rotation, N1 = 1000 rpmSpeed of rotation, N2 = 250 rpmCentre distance, a = 800 mmGear ratio, i = N1/N2 = 4istd = 4Teethes, z1 = 20Teethes, z2 = i * z1 = 80 teethChain pitch, a = (30 50) pa = 30p => p= 26.67 mm =pmaxa = 50p => p= 16 mm =pminStandard pitch, pstd =25.4 mmSo the chain selected is 16A1-R80-> simplexLength of chain,lp = 2ap + (z1+z2)/2+((z2-z1)/2)2/apap = ao/p = 800/25.4 = 31.49lp = (2*31.49)+50+(60/2*3.14)2/31.49= 115.87= 116 linksActual length = no. of links * pitch= 2946.6 mmBearing area = 1.79 mm2Centre distance, a = ((e+(e2-8m))/4)pe = lp (z1+z2)/2 = 66m = ((z2-z1)/(2*3.14))2= 91.18a = 66+(((662 (8*91.18))/4)p = 801.5 mm

2. Design calculation for chain driveSpeed of rotation, N1 = 1000 rpmSpeed of rotation, N2 = 250 rpmCentre distance, a = 1200 mmGear ratio, i = N1/N2 = 4istd = 4Teethes, z1 = 20Teethes, z2 = i * z1 = 80 teethesChain pitch, a = (30 50)pa = 30p => p= 40 mm =pmaxa = 50p => p= 24 mm =pminStandard pitch, pstd =25.4 mmSo the chain selected is 16A1-R80-> simplexLength of chain,lp = 2ap + (z1+z2)/2+((z2-z1)/2)2/apap = ao/p = 1200/25.4 = 47.24lp = (2*47.24)+50+(60/2*3.14)2/47.24= 144.49= 146 linksActual length = no. of links * pitch= 3708.4 mmBearing area = 1.79 mm2Centre distance, a = ((e+(e2-8m))/4)pe = lp (z1+z2)/2 = 96m = ((z2-z1)/(2*3.14))2= 91.18a = 96+(((962 (8*91.18))/4)p = 1194.5 mm

3. Rotation reduction ratiosSteering rotation = 7200Angle of cam to be tilted = 900So value of angle to be reduced is in ratio 8:1The reduction between the sprockets is made as 4:1So the diameter & teeth of the larger sprocket should be four times that of the smallerDiameter, d1 = 40 mmTeethes, z1 = 20Diameter, d2 = 160 mmTeethes, z1 = 80

4. Design calculation for spur gearsSpeed of rotation, N1 = 1000 rpmSpeed of rotation, N2 = 500 rpmGear ratio, i = N1/N2 = 2Assuming the same material for pinion and gear 16Ni 1 Cr80Life of gear = 20,000 hoursNumber of cycles = 20,000*60*N1= 20,000*60*1000= 1.2*109cyclesYoungs modulus, E = 2.15*106 kgf/cm2= 2.15*105 N/mm2Design contact stress, [c] = CR * HRC*KclCR = 310, HRC = 60, Kcl= 1 {from psg tech data book pg.No.8.17}[c] = 18.6 * 102 N/mm2Design bending stress, [b] = ((1.4*Kbl*-1)/(n*K))N = 2, K = 1.2, Kbl = 1-1 = 0.25u + 1200u = 1000 N/mm2-1 = 47000 N/cm2[b] = 274.16 N/mm2k.kd = 1.3ko = 1.5(medium shock)Teethes, z1 = 20Teethes, z2= i*z1 = 40

5. Design calculation for sprockets

Here the rotation reduction ratio is 4:1So the diameter & teeth of larger sprocket should be four times that of the smaller.Diameter, d1 = 40 mm [readily available in market]Teethes, z1 = 20Diameter, d2 = 160 mmTeethes, z2 = 80

6. Design calculation for cam & follower

OA = initial position of light bracket (7inches)AB = final position of light bracketOB = distance moved by the bracketStroke length = 102.6 mmCam diameter = 150 mmFollower length = 102.6 mm

7. Sprocket & Gear details, we selected due to availability in market:S. No.ComponentMaterialNo. of teethDiameter

1Small SprocketMild steel2040

2Large SprocketMild steel80160

3Small GearMild steel2040

4Large GearMild steel4080

Real life road traffic situationsNegotiating a bend With directional headlightwithout directional headlight

Arriving at a junction With directional headlight Without directional headlight

ADVANTAGES Useful for heavy vehicles in hill areas, where hair-pin bends are more. Safe riding Accident free roads Simple in structure Mind free drivingLIMITATIONS Not mandatory for straight roads.APPLICATIONS Can be used in all heavy vehicles. Can be used in tempo and vans.

ConclusionsBefore we undertook this project our knowledge about directional headlights was limited. After doing an extensive research for this project we have a wider knowledge of this field in automotive technology, learnt useful informationabout different types of directional headlights. We have searched the library of the college for relevant books and the internet for additional information. During the build of an experimental model of directional headlights on a vehicle we have improved our DIY skillsand technical problem solving ability .Carrying out test with the project vehicle has proved that this concept works and although such lights are not widely used even nowadays, it does support the drivers vision during night-time driving, helps toreduce black spots while cornering and therefore reduces the risk of accidents, by helping to notice persons or objects hidden in a bend earlier in advance. We are looking forwardto see more road vehicles equipped withdirectional headlights in serial production.

BIBLIOGRAPHYLibrary:Birch, Thomas W. (1993) Automotive suspension and steering systems. Fort Worth: Suanders College PublishingDenton, Tom. (2000)Automobile electrical and electronicsystems.W. InternationalEllinger, Herbert E. and Hathaway, Richard B.(1989) Automotive suspension and steeringsystems. Englewood Cliffs, N.J.: Prentice Hall Rendle, Steve (2005)Ford Fiesta service and repair manual, Oct 1995-Mar 2002 (N to02registration) petrol and diesel. Sparkford, Somerset: Haynes Service Publications (1995)Owners guide, Fiesta. 5th edition. Brentwood, Essex: Ford Motor Company Ltd.PSG Design Data BookInternet: BMW Group Citroen ID/DS Club Nederland Wikicars Wikipedia